How is your calculus?
Let do it with a cubic d*x3+c*x2+b*x+a
Differentiate to give 3d*x2+2c*x+b This will = 0 if the value is min or max
Now we could solve this quadratic but with a 6th order fit the differential
will be a 5th order equation for which there is no closed solution.

You cannot make Solver behave like a function but you can make a macro to
run Solver (look in MS Knowledge database, I think there is an example
there; or try www.solver.com)
best wishes
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"Ralph" wrote in message
...
I have a 6th order polynomial fit of data points. I want to find the
number
that would give the maximum value of this curve. Is there a formula that
would do this without creating a large table and evaluating the table for
the
Max?
(eg. derivative where slope = 0 indicates maximum)